Remote data monitoring in the existing industry control process is mostly realized by using the data network, such as Internet or LAN. No matter what the structure details of the remote data monitoring system is, its general connection way is shown in FIG. 1, that is, the system comprises a process control computer, an industry process controlled by the process control computer and a remote monitoring computer connected with the process control computer.
The remote monitoring system is characterized in that the process control computer is physically connected with the external network through network, and the physical connection may result in attack on the process control computer from the external network, such as hacker attack from network or virus invasion. Although protective measures like firewalls can be applied in the computer system, it is still impossible to guarantee absolute safety of the process control computer. Since the process control computer performs real-time industrial control or monitoring on the controlled industry process, once it is attacked, it may cause out-of-control of the controlled industry process so as to cause serious consequences.